HUE035813T2

HUE035813T2 - Advanced ultra supercritical steam generator

Info

Publication number: HUE035813T2
Application number: HUE14187421A
Authority: HU
Inventors: Paul S Weitzel
Original assignee: Babcock & Wilcox Co
Priority date: 2013-10-03
Filing date: 2014-10-02
Publication date: 2018-05-28
Also published as: US20150096507A1; TWI615542B; EP2857746A1; US9874346B2; TW201529956A; AU2014213495B2; EP2857746B1; AU2014213495A1; CA2865665A1; BR102014021446A2; CN104515125A; PL2857746T3; CL2014002508A1; ES2632435T3; NZ629103A; CN104515125B

Abstract

A supercritical steam generator includes a downdraft furnace enclosure, a hopper tunnel, and a convection pass enclosure, with the hopper tunnel joining the downdraft furnace enclosure and convection pass enclosure together. Flue gas passes down through the downdraft furnace enclosure through the hopper tunnel and up through the convection pass enclosure. This structure permits the outlet steam terminals, which provide access to the resultant supercritical steam and/or reheat steam, to be located at a base of the steam generator rather than at the top of the steam generator as with conventional boilers. This reduces the length of the steam leads from the steam generator to a steam turbine that produces electricity using the supercritical steam.

Description

BACKGROUND

[0001] The present disclosure relates to steam generating systems which can be used in combination with carbon capture sequestration (CCS) technology for use in coal-fired power generation.

[0002] During combustion, the chemical energy in a fuel is converted to thermal heat inside the furnace of a boiler. The thermal heat is captured through heat-absorbing surfaces in the boiler to produce steam. The fuels used in the furnace include a wide range of solid, liquid, and gaseous substances, including coal, natural gas, and diesel oil. Combustion transforms the fuel into a large number of chemical compounds. Water and carbon dioxide (CO2) are the products of complete combustion. Incomplete combustion reactions may result in undesirable byproducts that can include particulates (e.g. fly ash, slag), acid gases such as SOx or NOx, metals such as mercury or arsenic, carbon monoxide (CO), and hydrocarbons (HC).

[0003] Figure 1 illustrates the steam-water flow system and the gas flow system for a conventional once-through two pass Carolina-style boiler 10 with a furnace 20 capable of operating at subcritical to supercritical pressure. As is known, the boiler 10 includes fluid cooled membrane tube enclosure walls typically made up of wa-ter/steam conveying tubes 30 separated from one another by a steel membrane (not visible) to achieve a gastight enclosure. The tubes 30 are referred to herein as water tubes for brevity and simplicity.

[0004] The steam generator operates with a variable pressure profile versus load (subcritical to supercritical pressure). The water enters the economizerthrough inlet 141 and absorbs heat, then travels from economizer outlet 142 to inlet 143 at the base of the furnace. A lower bottle (not shown) maybe present to distribute this water. The water then travels up through the furnace wall tubes 30. As the water travels through these water tubes 30, the water cools the tubes exposed to high-temperature flue gas in the combustion chamber 60 and absorbs energy from the flue gas to become a steam-water mixture at subcritical pressure (and remains a single phase fluid if at supercritical pressure conditions). The fluid is discharged into the vertical steam separators 42, where the steam-water mixture is separated, when subcritical, into wet steam (i.e., saturated steam) and water. Any water can exit via downcomer 50 and pass from outlet 144 to the economizer inlet 141. When the fluid is supercritical, the vertical separators act as conveying pipes with all the entering steam leaving from the top outlets. The steam is used to cool the flue gas in the convection pass path 70 of the furnace through steam tubes or roof tubes 75 leading from the vertical separator. The steam then passes from outlet 149 to inlet 145 and is fed through superheater heating surface 80, then sent to the high pressure steam turbine (reference number 146). Steam returning from the high pressure steam turbine (reference number 147) passes through the reheater heating surface 90 to absorbing additional energy from the flue gas, and can then be sent to a second intermediate-pressure or low-pressure steam turbine (reference number 148). The steam sent to the turbines is generally dry steam (100% steam, no water). The steam from the superheater 80 heating surfaces can be sent to a high pressure (HP) turbine, then from the reheater 90 heating surface to the intermediate pressure (IP) and low pressure (LP) steam turbine stages (not shown). Feedwater conveyed through economizer 100 may also be used to absorb energy from the flue gas before the flue gas exits the boiler; the heated feedwater is then sent to the furnace enclosure tubes 30, or can be sent through superheater 80 and reheater 90.

[0005] Referring to the gas flow system, air for combustion can be supplied to the furnace 20 through several means. Typically, a fan 102 supplies air 104 to a regenerative air heater 106. The heated air is then sent as secondary air 108 to windboxes for distribution to individual burners and as primary air 110 to the coal pulverizer 112, where coal is dried and pulverized. The primary air (now carrying coal particles) 116 is then sent to the burners 120 and mixed with the secondary air 108 for combustion and formation of flue gas 130 in the combustion chamber 60. The flue gas flows upwardly through the furnace combustion chamber 60 and then follows the convection pass path 70 to flue gas exhaust 160 past superheater 80, reheater 90, and economizer 100. The flue gas can then be passed through the regenerative air heater 106 (to heat the incoming air 104) and pollution control equipment 114 and, if desired, recycled through the furnace 20. The flue gas exits the boiler 10 through the flue gas exhaust 160.

[0006] Figure 1 also illustrates the start up equipment of the steam-water flow system. When the steam is supercritical, a vertical steam separator 42 is used instead of a conventional horizontal steam drum of a subcritical natural circulation boiler. A boiler circulation pump 44 and shut-off valve 46 are also present in the downcomer 50 to augment the flow in the furnace enclosure walls 30 and the economizer 100 during start-up. The boiler circulation pump is stopped at the load where 100% dry steam is entering the vertical steam separator from the furnace enclosure. The vertical steam separator remains in service and a static column of water remains in the downcomer 50.

[0007] As illustrated here, the steam outlet terminals of a Carolina style boiler are located at the top of the boiler, generally at a relatively high elevation from grade of about 61 meters (200 feet). The steam is then carried to a steam turbine via steam leads (i.e. pipes). The steam leads are made from a nickel alloy for 700°C steam temperatures, which is very expensive. Due to the location of the steam outlet terminals at the top of the boiler, the length of the steam leads can be very great. It would be desirable to be able to reduce the length of the steam leads from the steam outlet terminals of the boiler to the steam turbine where the steam is used to generate electricity. US 2013/239909 A1 discloses an arrangement structure suitable for an invertted pulverized coal boiler with ultra-high steam temperature steam parameters, including a hearth, wherein the hearth is communicated with a middle uplink flue, and the top of the middle uplink flue is communicated with that of a tail downlink flue. US 2009/188448 A1 discloses an apparatus that extracts energy from processed agricultural residue (PAR).

SUMMARY

[0008] Particular aspects and embodiments aresetout in the appended independent and dependent claims. [0009] The present disclosure relates to a boiler system which can be used in conjunction with a steam turbine to generate electricity. The steam outlet terminals of the boiler are located at the base of the boiler, instead of at the top of the boiler. This reduces the needed length of the steam leads, in turn reducing the cost and improving the economics of the overall system.

[0010] Disclosed in various embodiments herein is a steam generator, comprising: a downdraft furnace enclosure formed from walls made of water or steam cooled tubes, and wherein the furnace walls define a top end and a bottom gas outlet; a convection pass enclosure including a bottom gas inlet and horizontal tube banks located above the bottom gas inlet; a hopper tunnel connecting the bottom gas outlet of the downdraft furnace enclosure to the bottom gas inlet of the convection pass enclosure, the hopper tunnel including a submerged chain conveyer for removing ash and slag, the submerged chain conveyer forming a closure of the hopper tunnel; and a steam outlet terminal located at the base of the steam generator.

[0011] The bottom gas outlet of the downdraft furnace enclosure may include an outwardly-extending throat that extends into a porthole of the bottom gas inlet of the convection pass enclosure.

[0012] The top end of the downdraft furnace enclosure may include a gas inlet for receiving flue gas from an associated furnace.

[0013] The steam generator further comprises a wind-box and burners at the top end of the downdraft furnace enclosure for generating flue gas.

[0014] The flue gas exiting the convection pass enclosure may be recirculated to the top end of the downdraft furnace enclosure, to a base of the downdraft furnace enclosure, and/or to a base of the convection pass enclosure.

[0015] The flue gas exiting the convection pass enclosure may pass through a particulate cleaning device and then be recirculated to the top end of the downdraft furnace enclosure, a base of the downdraft furnace enclosure, ora base of the convection pass enclosure.

[0016] The hoppertunnel may be lined with a refractory material. The submerged chain conveyor may travel inline with the flue gas flow, or may travel transverse to the flue gas flow.

[0017] Alternatively, the hoppertunnel can be formed from steam or water-cooled tube panels. Water trough seals may be present between the downdraft furnace enclosure, the hopper tunnel, and the convection pass enclosure.

[0018] The fluid in the tubes of the downdraft furnace enclosure can flow counter-current to flue gas flow. [0019] The convection pass enclosure is sometimes formed from enclosure walls made of steam or water cooled tubes, wherein the cooling fluid in the tubes of the convection pass enclosure flow co-current to flue gas flow.

[0020] The horizontal tube banks in the convection pass enclosure may include superheaters, reheaters, and economizers.

[0021] The steam generator may further comprise an upper horizontal pass enclosure connected to a top end of the convection pass enclosure and a down pass, the upper horizontal pass and the down pass containing additional tube banks.

[0022] These and other non-limiting characteristics are more particularly described below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The following is a brief description of the drawings, which are presented for the purposes of illustrating the example embodiments disclosed herein and not for the purposes of limiting the same.

Figure 1 is a schematic diagram illustrating a conventional two-pass (Babcock and Wilcox Carolina-style) subcritical or supercritical once through type steam generator

Figure 2 is a side perspective view of a first example embodiment of a once through steam generator of the present disclosure, wherein the inverted tower downdraft furnace enclosure includes the burners that generate the flue gas.

Figure 3 is a cross-sectional view of one possible design for the hopper tunnel, with conveyors traveling transverse to the flue gas flow. The hopper tunnel is an in-ground refractory lined, concrete and steel arch way to transfer the flue gas flow.

Figure 4 is another embodiment of the hopper tunnel, being formed from steam or water-cooled tube panels.

Figure 5 is a perspective view showing a variation of the hopper tunnel having a vertical wall.

Figure 6 is a front view of the hoppertunnel of Figure 5.

Figure 7 is aside view of the hoppertunnel of Figure 5.

Figure 8 is a side view of another example embodiment of a downdraft inverted tower steam generator of the present disclosure, showing the steam turbine in relation to the steam generator.

Figure 9 is a perspective view of another embodiment of a downdraft inverted tower steam generator and the steam turbine piping.

Figure 10 is a side view (along an imaginary y-axis) of the steam generator of Figure 9.

Figure 11 is a front view (along an imaginary x-axis) of the steam generator of Figure 9.

Figure 12 is a plan view (i.e. from the top) of the steam generator of Figure 9.

Figure 13 is a side view showing the steam turbine at the same grade as the modified tower steam generator (i.e. in the conventionally expected relative position).

Figure 14 is a plan view (i.e. from the top) showing additional details of the modified tower steam generator of Figure 13.

Figure 15 is a side view of an embodiment where the modified tower steam generator has a base elevation difference compared to the steam turbine. Figure 16 is a side view of an embodiment where the modified tower steam generator has the same base elevation as the steam turbine.

Figure 17 is a side view of another example embodiment of a steam generator of the present disclosure, wherein the bottom gas outlet of the downdraft furnace enclosure is shaped as a throat that enters a porthole of the bottom gas inlet of the convection pass enclosure.

DETAILED DESCRIPTION

[0024] A more complete understanding of the components, processes, and apparatuses disclosed herein can be obtained by reference to the accompanying drawings. These figures are merely schematic representations based on convenience and the ease of demonstrating the present disclosure, and are, therefore, not intended to indicate relative size and dimensions of the devices or components thereof and/or to define or limit the scope of the described embodiments.

[0025] Although specific terms are used in thefollowing description for the sake of clarity, these terms are intended to refer only to the particular structure of the embodiments selected for illustration in the drawings, and are not intended to define or limit the scope of the disclosure. In the drawings and the following description below, it is to be understood that like numeric designations refer to components of like function.

[0026] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0027] As used in the specification and in the claims, the term "comprising" may include the embodiments "consisting of and "consisting essentially of." [0028] Numerical values should be understood to include numerical values which are the same when re duced to the same number of significant figures and numerical values which differ from the stated value by less than the experimental error of conventional measurement technique of the type described in the present application to determine the value.

[0029] All ranges disclosed herein are inclusive of the recited endpoint and independently combinable (for example, the range of "from 2 watts to 10 watts" is inclusive of the endpoints, 2 watts and 10 watts, and all the intermediate values).

[0030] As used herein, approximating language may be applied to modify any quantitative representation that may vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as "about" and "substantially," may not be limited to the precise value specified, in some cases. The modifier "about" should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression "from about 2 to about 4" also discloses the range "from 2 to 4." [0031] The terms "waterside", "water cooled", "steam cooled" or "fluid side" refer to any area of the boiler that is exposed to water or steam. In contrast, the terms "air-side", "gas side" or "fireside" refer to an area of the boiler that is exposed to direct heatfrom the furnace, or in other words the combustion gas from the furnace. Where the specification refers to water and/or steam, the liquid and/or gaseous states of other fluids may also be used in the methods of the present disclosure.

[0032] It should be noted that many of the terms used herein are relative terms. For example, the terms "upper" and "lower" are relative to each other in location, i.e. an upper component is located at a higher elevation than a lower component in a given orientation. The terms "inlet" and "outlet" are relative to a fluid flowing through them with respect to a given structure, e.g. a fluid flows through the inlet into the structure and flows through the outlet out of the structure. The terms "upstream" and "downstream" are relative to the direction in which a fluid flows through various components, i.e. the flow fluids through an upstream component prior to flowing through the downstream component.

[0033] The terms "horizontal" and "vertical" are used to indicate direction relative to an absolute reference, i.e. ground level. However, these terms should not be construed to require structures to be absolutely parallel or absolutely perpendicular to each other. For example, a first vertical structure and a second vertical structure are not necessarily parallel to each other. The terms "top" and "bottom" or "base" are used to refer to surfaces where the top is always higher than the bottom/base relative to an absolute reference, i.e. the surface of the earth. The terms "above" and "below" are used to refer to the location of two structures relative to an absolute reference. For example, when the first component is located above a second component, this means the first component will always be higher than the second component relative to the surface of the earth. The terms "upwards" and "down wards" are also relative to an absolute reference; an upwards flow is always against the gravity of the earth. [0034] As used herein, the term "supercritical" refers to a fluid that is at a temperature above its critical temperature or at a pressure above its critical pressure or both. For example, the critical temperature of water is 374.15 °C, and the critical pressure of water is 3200.1 psia (22.1 MPa). A fluid at a temperature that is above its boiling point at a given pressure but is below its critical pressure is considered to be "superheated" but "subcrit-ical". A superheated fluid can be cooled (i.e. transfer energy) without changing its phase. As used herein, the term "wet steam" refers to a saturated steam/water mixture (i.e., steam with less than 100% quality where quality is percent steam content by mass). As used herein, the term "dry steam" refers to steam having a quality equal to greater than 100% (i.e., no liquid water is present). Supercritical water or steam will have no visible bubble interface or meniscus forming during a heating or cooling process due to zero surface tension on reaching the critical point temperature. The fluid continues to act like a single phase flow while converting from water to steam or steam to water, and is a non-equilibrium thermodynamic condition where rapid changes in density, viscosity and thermal conductivity can occur.

[0035] To the extent that explanations of certain terminology or principles of the solar receiver, boiler and/or steam generator arts may be necessary to understand the present disclosure, the reader is referred to Steam/its generation and use, 40th Edition, Stultz and Kitto, Eds., Copyright 1992, The Babcock & Wilcox Company, and to Steam/its generation and use, 41st Edition, Kitto and Stultz, Eds., Copyright 2005, The Babcock & Wilcox Company, the texts of which are hereby incorporated by reference as though fully set forth herein.

[0036] In the conventional boiler of Figure 1, the steam outlet terminals are at the top center of the structure. The top of the structure is relatively high, about 61 to 76 meter (200 to 250 feet). Such a height is necessary for the furnace to have a volume sufficient for the coal particles to be completely combusted, for the water tubes to absorb the heat energy, and to lower the flue gas temperature below the ash fusion temperature (minimizing slagging and fouling in the various tube banks). It is desirable to also lower the height of the steam outlet terminals, so as to bring them closerto the steam turbine and offer a shorter overall setting height. The present disclosure relates to such a steam generatorwritten. In particular, the steam generator of the present disclosure is an advanced ultra supercritical steam generator, which can produce an outlet steam pressure of 25 MPa (3625 psia) or higher, including 29 MPa (4200 psia) orhigher; and an outlet steam temperature of 570°C (1058°F) or higher, including 730°C (1346°F) or higher. Unlike the natural circulation drum boiler where the furnace enclosure walls operate at nearly uniform temperatures close to saturation temperature, the advanced ultra supercritical once through steam generator of the present disclosure does not have fairly uniform enclosure wall temperatures near saturation. The conventional once through supercritical steam generator must be carefully designed to have fairly narrow differences and very similar geometry, thermo hydraulic flow characteristics and heat absorption conditions on all of the welded enclosure wall tubes. The present design thus permits the joining of a series of separate enclosures along the gas flow path which can operate at different material temperatures.

[0037] In the Carolina (two-pass) boiler of Figure 1, the flue gas flows upwards, then horizontally and downwards through the tube banks. In the steam generators of the present disclosure, this gas flow path is reversed. The flue gas first flows downwards, then horizontally and then upwards through tube banks that convert the water to superheated or supercritical steam. This arrangement allows the steam terminals to be lower (closer to the ground) and closer to the steam turbine.

[0038] Figure 2 is a side perspective view of a first example embodiment of a steam generator 200 of the present disclosure. The steam generator generally includes three structures: a downdraft furnace enclosure 210, a hopper tunnel 270, and a convection pass enclosure 230. The downdraft furnace enclosure is shown here on the left. The downdraft furnace enclosure 210 is formed from walls 216 made of water or steam cooled tubes, which may be arranged vertically or spirally. The furnace enclosure walls 216 define a top end 212 and a bottom end 214. The top end and the bottom end are at opposite ends of the furnace walls. As illustrated here, a windbox 218 and burners 220 are located near the top end of the furnace. The burners may be arranged in the roof (i.e. the top end) or at the top of the furnace walls. Burners may be located on all four walls, opposed on two of the walls, or near the corners of the four walls.

[0039] In use, air and coal are fed into the top end 212 by the windbox or roof vestibule 218, and combusted using the burners 220 to generate hot flue gas 202. Oxy-combustion (i.e. using oxygen-enriched recirculated gas) or air firing can be used. The windbox also generates an air flow that causes the flue gas to flow downwards due to mechanical draft fans (rather than rising as would naturally occur; the downdraft is aided by the wall cooling the flue gas). A bottom gas outlet 222 is present at the bottom end 214, through which the hot flue gas exits the furnace enclosure 210. The flue gas flows through a hopper tunnel 270 located at the base of the furnace enclosure. The hopper tunnel 270 fluidly connects the bottom gas outlet 222 of the downdraft furnace enclosure with a bottom gas inlet 236 of the convection pass enclosure. The hopper tunnel also flexibly seals the bottom gas outlet and the bottom gas inlet. When exiting the downdraft furnace enclosure, the flue gas may have a temperature of about 500°F to about 2500°F. The flue gas 202 then flows upwards through the convection pass enclosure 230 past horizontally arranged tube banks that act as superheater 240, reheater 242, and/or economizer 244 surfaces. These surfaces capture additional energy from theflue gas. When exiting the convection pass enclosure, the flue gas may have a temperature of about 116°C (240°F) to about 441 °C (825°F). The convection pass enclosure 230 itself also has a top end 232 and a bottom end 234.

[0040] The flue gas may pass through a regenerative air heater to transfer some of the remaining heat energy to incoming air. Theflue gas may also be sent to pollution control units to remove undesired byproducts. For example, the flue gas can pass through a selective catalytic reduction (SCR) unit to remove NOx, a flue gas desulfurization (FGD) unit to remove SOx, and/or a particulate cleaning device (e.g. a baghouse or electrostatic precipitator). The pollution control units and the regenerative air heater are placed in an order suitable for optimum pollution reduction. For example, in specific embodiments, the SCR unit is placed upstream of the regenerative air heater. If desired, the flue gas exiting the convection pass enclosure may be recirculated to the wind-box or vestibule 218 at the top of the furnace enclosure, a practice generally referred to as gas recirculation. If desired, the flue gas exiting the convection pass enclosure can also be recirculated to the base 252 of the down-draft furnace enclosure for steam temperature control and/or to the base 254 of the convection pass enclosure and used to control the flue gas temperature, which is generally referred to as gas tempering. The steam generator may include any of these recirculation paths, or may include all three recirculation paths.

[0041] With regard to the fluid flow in the downdraft furnace enclosure, relatively cold water from the economizer outlet enters the steam generator at the base of the furnace walls 216, and flows through the water tubes, becoming a steam/water mixture by absorbing the heat energy in the flue gas. This water flows counter-current to the flue gas flow (i.e. the water flows upwards while the flue gas flows downwards). The steam/water mixture is collected in outlet headers and sent to vertical steam separators 260 and separated into wet steam and water. The steam is sent to the convection pass enclosure 230 through the superheater 240 then to the steam turbine, and then returns from the steam turbine to pass through the reheater 242 tube banks in the convection pass enclosure. In some embodiments, the convection pass enclosure is also formed from enclosure walls made of wa-terorsteam cooled tubes, which can also capture energy. In such embodiments, the fluid flow in the enclosure walls of the convection pass enclosure is co-current to the flue gas flow (i.e. both flow upwards). Generally, the down-draft furnace enclosure is water-cooled at lower loads and becomes steam cooled near the outlet at higher loads, while the convection pass enclosure is steam-cooled.

[0042] The supercritical steam and/orreheatsteam exits at one or more steam outlet terminals located at the base 264 of the convection pass enclosure, which is part of the steam generator. The reheat steam outlet terminal is labeled with reference numeral 261, while the super critical steam outlet terminal is labeled with reference number 262, and either or both of these outlet terminals may be present. The term "base" refers here to the bottom one-third of the steam generator’s height. For example, if the steam generator has a height of about 18 meters (60 feet), then the steam outlet terminal(s) is at a height of at about 6.1 meters (20 feet). It should be recognized that the furnace enclosure and the convection pass enclosure may be of different heights.

[0043] In this regard, the steam leads for main steam and hot reheat piping needed to operate an advanced ultra supercritical steam generator at 700°C (1292°F) are as much as four (4) times the cost of material by mass for the steam leads needed to operate a steam generator at 600°C (1112°F). It can thus be advantageous to use the present design to lowerthe steam outlet terminal rather than incur the cost of such piping.

[0044] The tube banks in the convection pass enclosure should be drainable. Internal deposits are generally dispersed along the tube rows, so as not to concentrate in the lower bends of pendant sections. At the connection to the enclosure walls, expansion water seals orgas tight expansion joints (not shown) are present between the enclosure walls and the tube banks.

[0045] Returning to Figure 2, the hopper tunnel 270 flexibly connects the downdraft furnace enclosure 210 to the convection pass enclosure 230. The hopper tunnel is desirably adiabatic. The hopper tunnel 270 includes one or more ash and slag outlets connected to submerged chain conveyor(s) 274. It is contemplated that ash and slag fall into the submerged chain conveyor(s) and are disposed of. The chain conveyor can either be in-line with the flue gas flow, or can be transverse to the flue gas flow. As illustrated here, the chain conveyor is in-line.

[0046] Figure 3 is an alternative embodiment of the hopper tunnel 270, in which the chain conveyors are transverse to the flue gas flow 202. Two submerged chain conveyors 474 are visible in the hopper tunnel 270 under the downdraft furnace enclosure 210 and the convection pass enclosure 230. As seen here, one difference is that the base 412 of the downdraft furnace enclosure and the base 432 of the convection pass enclosure are sloped to guide the ash/slag into the submerged chain conveyors.

[0047] Figure 4 is another embodiment of the hopper tunnel. Here, the hoppertunnel is also formed from steam or water-cooled tube panels. The tube panels 500 forming the sides of the hoppertunnel are bottom-supported, while the roof 502 of the hopper tunnel is top-supported using the side walls of the hopper tunnel. Water trough seals or nonmetallic seals 504 can be made between the hoppertunnel 270, the downdraft furnace enclosure 210, and the convection pass enclosure 230. The chain conveyor 274 is illustrated as forming the closure of the hopper tunnel.

[0048] Figures 5-7 are various views illustrating another possible variation on the structure of the hopper tunnel 270. The downdraft furnace enclosure 210 is on the left, and the convection pass enclosure 230 is on the right. The bottom of the hopper tunnel contains two submerged chain conveyors 474. The base 412 of the down-draft furnace enclosure is sloped to guide the ash/slag into the conveyors. In addition, a vertical wall 292 is located in the hopper tunnel between the two conveyors. The base 294 of the vertical wall is sloped laterally in both directions to guide the ash/slag into the conveyors. Arches 296 are present in the centerof the hoppertunnel, and can be used to support the top tube panels 502 of the hoppertunnel. The vertical wall may have any desired length. Water trough seals 504 between the hopper tunnel, the downdraft furnace enclosure, and the convection pass enclosure are also visible. It is contemplated that ground level would be at the level of the water trough seals. The tunnel itself can be out of concrete, refractory, and dirt. Water cooling tube circuits can be placed in the walls and/or arches of the tunnel.

[0049] Referring specifically to Figure 6, it should be noted that the base 294 of the vertical walls are sloped to create a funnel for the ash/slag, with the resulting opening 480 having a width 482 that is less than the width 484 of the submerged chain conveyor 486. The maintenance position for the conveyor is depicted here 488. It is contemplated that as needed for maintenance or other purposes, the conveyors can be switched out.

[0050] Because the furnace enclosure and the convection pass enclosure are designed to operate at a high temperature differential, the hoppertunnel 270 must be able to handle the transfer of very hot flue gas. The hopper tunnel may be lined with a refractory material 276, which is chemically and physically stable at high temperatures. Examples of suitable refractory materials include refractory brick containing aluminum oxide, silica, or magnesium oxide, or ceramic tiles. Such materials can withstand temperatures of 1538°C (2800°F) to 1649°C (3000°F). As illustrated here, the hopper tunnel has a width 282, refractory brick 276 located around the entire periphery of the tunnel, and insulation 278 surrounding the brick, and having the appropriate dimensions. The upper portion of the hoppertunnel has a height 284, and the lower portion of the hopper tunnel has a height 286. Present in the lower portion is a mechanical transport system 280 (e.g. a submerged chain conveyor) that moves the ash out of the hopper tunnel.

[0051] Figure 8 is a side view of an embodiment of the downdraft inverted tower steam generator and steam turbine. The downdraft furnace enclosure 1010 is on the left, and the convection pass enclosure 1030 is on the right. The steam turbine 1100 is on the far right. The solid lines 1122 represent the steam leads that carry the supercritical steam and/or reheat steam to the steam turbine. The dotted rectangles 1128 represent reheaters / superheaters. The rectangles 1156 represent economizers. The rectangle 1134 represents a separate low pressure steam generator to produce auxiliary steam for utility purposes. The hopper tunnel 270 is also shown here.

Again, the base 412 is sloped longitudinally to direct ash/slag into the conveyors 474.

[0052] Figures 9-12 are various drawings showing another embodiment of a steam generator. This embodiment contains the downdraft furnace enclosure 1010, hopper tunnel 1070, and convection pass enclosure 1030, and also contains additional down pass 1092. [0053] Figure 9 is a perspective view of the exterior of the steam generator. The downdraft furnace enclosure 1010 is on the far left, and the convection pass enclosure 1030 is in the center. The hopper tunnel 1070 is the triangular structure linking the base of the convection pass enclosure 1030 with the base of the downdraft furnace enclosure 1010. The down pass 1092 is the structure on the far right. The rectangle at the bottom of the hopper tunnel represents the chain conveyor 1074 that removes ash/slag. The solid lines 1122 represent the steam outlet piping. The circles 1126 represent burner openings at the top of the downdraft furnace enclosure. Reference numeral 1120 is the structure connecting the convection pass enclosure 1030 with the down pass 1092.

[0054] Figure 10 is a side view (along an imaginary y-axis) of the steam generator and the steam turbine. The dotted rectangles 1128 represent the horizontal tube banks that serve as reheaters / superheaters, and provide the outlet steam terminals near the base of the steam generator/convection pass enclosure. The dashed lines 1122 represent the steam leads that carry the supercritical steam and/or reheat steam to the steam turbine. The steam turbine 1100 is contained in a building marked by reference numeral 1130. It should be noted that the steam turbine is located on elevation 1132, relative to the steam generator.

[0055] Figure 11 is a front view (along an imaginary x-axis) of the steam generator and the steam turbine. The convection pass enclosure 1030 is not fully visible here, because it is behind the building containing the steam turbine. The additional down pass 1092 is seen on the right. Again, the dotted rectangles 1128 represent the reheaters / superheaters. The stippled rectangles 1156 represent horizontal tube banks that serve as econ-omizers. The solid black rectangle 1134 represents a separate low pressure steam generator to produce auxiliary steam for utility purposes such as sootblowing. Using a lower temperature coolant helps reduce flue gas temperature and does not use super-elevated high temperature high pressure steam for lower level services. The striped rectangle 1136 represents a space for future heating surfaces to be installed (e.g. for modifications during the service life of the steam generator). The steam turbine is marked as reference numeral 1100.

[0056] Figure 12 is a plan view (i.e. from the top) of the steam generator 1000 and steam turbine 1100. As seen here, the lines 1122 illustrate the steam leads that feed the steam turbine. The steam leads run from the steam outlet terminals 1062 on the convection pass enclosure 1030 to multiple locations on the steam turbine. [0057] Figure 13 is a side view (along an imaginary x- axis) of another embodiment of a modified tower steam generator and the steam turbine. The dotted rectangles 1128 represent reheaters / superheaters. The stippled rectangles 1156 represent economizers. The solid black rectangle 1134 represents a separate low pressure steam generator to produce auxiliary steam for utility purposes. The striped rectangle 1136 represents future heating surfaces. The secondary air duct 1140 leading from the regenerative air heater 1142 is also shown here. The dashed lines 1122 are the steam leads that feed the steam turbine 1100 with supercritical steam and/or reheat steam. The solid lines 1148 are feedwater and cold reheat steam lines from the feedwater heaters and the steam turbine.

[0058] Figure 14 is a plan view (i.e. from the top) showing additional details of the modified tower steam generator. The lines 1158 in the middle represent convection heating surface. The two circles 1144 on the right-hand side represent regenerative air heaters. The nine hexagonal shaped structures 1152 represent coal pulverizers. [0059] Figure 15 is a side view (along an imaginary x-axis) of the modified tower steam generator having a base elevation difference compared to the steam turbine 1100, which reduces steam line length. The structure 1154 in the center represents the furnace enclosure. The convection pass enclosure 1155 is above the furnace enclosure. The rectangle 1156 on the right represents the additional down pass downstream of the convection pass enclosure. The lines 1122 are the steam leads that feed the steam turbine 1100 with supercritical steam and/or reheat steam. The black lines 1148 are feedwater and cold reheat steam lines from the feedwater heaters and steam turbine. It should be noted that the black lines are run from the steam turbine to the horizontal convection pass enclosure, which is not completely visible here. Again, please note that the steam turbine is located on elevation 1132. Figure 16 is similar to Figure 15, except the steam turbine 1100 is located at the same elevation 1133 as the steam generator.

[0060] It is noted that the convection pass enclosure is depicted in the various Figures as having a single gas path. It is also contemplated that the convection pass enclosure can include parallel gas paths, where one gas path can be used for steam temperature control using gas biasing.

[0061] Figure 17 is a side view showing another embodiment of the downdraft inverted tower steam generator. This embodiment also includes a downdraft furnace enclosure 1010, a convection pass enclosure 1030, and a hopper tunnel 1070. As before, a bottom gas outlet is present at the bottom end of the downdraft furnace enclosure, and a bottom gas inlet is present at the bottom end of the convection pass enclosure. Here, the upper portion of the hopper tunnel isformed by the bottom ends of the downdraft furnace enclosure 1010 and the convection pass enclosure 1030. The bottom gas outlet 1022 of the downdraft furnace enclosure 1010 includes an outwardly extending nozzle that constricts in diameter as it extends from the walls 1016 of the flue tunnel to form a throat 1026. The bottom gas inlet 1036 of the convection pass enclosure 1030 includes an inward-facing porthole 1038. It is contemplated that the throat 1026 of the bottom gas outlet extends into the porthole 1038 of the bottom gas inlet to form a passageway through which the flue gas (arrow 1002) can flow from the downdraft furnace enclosure into the convection pass enclosure. It should be noted that the walls of the flue tunnel (1016) and the convection pass enclosure (1035) are notwelded together. However, the flat vertical faces of the two enclosures are placed closely together to permit the use of flexible gas-tight sealing toggle connections. In addition, stanchion bracing (not shown) may be used to control the relative movement of the two enclosures that may occur. The downdraft furnace enclosure 1010 and the convection pass enclosure 1030 include an opening into the lower portion of the hoppertunnel, where the submerged chain conveyor 274 is located. The various banks (reheat, superheat, economizer) in the convection pass enclosure 1030 are not illustrated here.

[0062] Therefore, from one perspective, there has been described a supercritical steam generator that includes a downdraft furnace enclosure, a hopper tunnel, and a convection pass enclosure, with the hoppertunnel joining the downdraft furnace enclosure and convection pass enclosure together. Flue gas passes down through the downdraft furnace enclosure through the hoppertunnel and up through the convection pass enclosure. This structure permits the outlet steam terminals, which provide access to the resultant supercritical steam and/or reheat steam, to be located at a base of the steam generator rather than at the top of the steam generator as with conventional boilers. This reduces the length of the steam leads from the steam generator to a steam turbine that produces electricity using the supercritical steam. [0063] The present disclosure has been described with reference to example embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the present disclosure be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims.

Claims 1. A steam generator (200), comprising: a downdraft furnace enclosure (210) formed from walls (216) made of water or steam cooled tubes, and wherein the furnace walls define a top end (212) and a bottom gas outlet; a convection pass enclosure (230) including a bottom gas inlet and horizontal tube banks located above the bottom gas inlet; a hoppertunnel (270) connecting the bottom gas outlet of the downdraft furnace enclosure to the bottom gas inlet of the convection pass enclo-sure, the hopper tunnel including at least one submerged chain conveyer (274) for removing ash and slag from the downdraftfurnace enclo-sure and the convection pass enclosure; a steam outlet terminal located at the base of the steam generator; and a windbox (218) and burners (220) at the top end of the downdraft furnace enclosure for generating flue gas. 2. The steam generator ofclaim 1, wherein the top end of the downdraft furnace enclosure includes a gas inlet for receiving flue gas from an associated furnace. 3. The steam generator of claim 1 or 2, wherein flue gas exiting the convection pass enclosure is recir-culated to one or more of the group comprising: the top end of the downdraft furnace enclosure; a base of the downdraft furnace enclosure; and a base of the convection pass enclosure. 4. The steam generator ofany preceding claim, wherein flue gas exiting the convection pass enclosure passes through one or more selected from the group comprising: a regenerative air heater (1142); and a particulate cleaning device; and is then recirculated to the top end of the downdraftfurnace enclosure, a base of the downdraft furnace enclosure, or a base of the convection pass enclosure. 5. The steam generator ofany preceding claim, wherein the hoppertunnel is lined with a refractory material. 6. The steam generator of claim 1, wherein the submerged chain conveyortravels in a direction relative to the flue gas flow, the direction selected from the group comprising: in-line with the flue gas flow; and transverse to the flue gas flow. 7. The steam generator ofany preceding claim, wherein the hopper tunnel is formed from steam or water-cooled tube panels (500, 502). 8. The steam generator of claim 7, wherein water trough seals (504) are present between the downdraft furnace enclosure, the hopper tunnel, and the convection pass enclosure. 9. The steam generator ofany preceding claim, wherein fluid in the tubes of the downdraft furnace enclosure flows counter-current to flue gas flow. 10. The steam generator ofany preceding claim, wherein the convection pass enclosure is formed from enclosure walls made of steam or water cooled tubes, wherein the cooling fluid in the tubes of the convection pass enclosure flow co-current to flue gas flow. 11. The steam generator ofany preceding claim, wherein the horizontal tube banks in the convection pass enclosure include superheaters (240), reheaters (242), and economizers (244). 12. 12. The steam generator of any preceding claim, wherein the steam generator further comprises an upper horizontal pass enclosure connected to a top end of the convection pass enclosure and a down pass, the upper horizontal pass and the down pass containing additional tube banks. 13. The steam generator ofany preceding claim, wherein the hopper tunnel is formed by an outwardly-ex-tending throat of the bottom gas outlet of the downdraft furnace enclosure that extends into a porthole ofthe bottom gas inlet of the convection pass enclosure. 14. The steam generator of claim 1, wherein the hopper tunnel includes a first submerged chain conveyer (474) below the downdraft furnace enclosure, and a second submerged chain conveyer (474) below the convection pass enclosure, the first and second submerged chain conveyers oriented transverse to the flue gas flow, a base (412) ofthe downdraft furnace enclosure sloped to guide ash/slag into the first submerged chain conveyer, and a base (432) ofthe convection pass enclosure sloped to guide ash/slag into the second submerged chain conveyer. 15. The steam generator of claim 1, wherein the submerged chain conveyer is oriented in-line with the flue gas flow, and passes below both the downdraft furnace enclosure and the convection pass enclosure.

Patentansprüche 1. Dampfgenerator (200), der Folgendes umfasst: eine Sturzbrandbrennkammerhülle (210), die aus Wänden (216) gebildet ist, die aus wasser-oder dampfgekühlten Rohren hergestellt sind, wobei die Brennkammerwände ein oberes Ende (212) und einen Bodengasauslass definieren; eine Konvektionsdurchgangshülle (230), die einen Bodengaseinlass und horizontale Rohrbänke, die über dem Bodengaseinlass angeordnet sind, enthält; einen Trichtertunnel (270), der den Bodengasauslass der Sturzbrandbrennkammerhülle mit dem Bodengaseinlass der Konvektionsdurchgangshülle verbindet, wobei der Trichtertunnel mindestens eine versenkte Kettenfördereinrich-tung (274) zum Entfernen von Asche und Schlacke aus der Sturzbrandbrennkammerhülle und der Konvektionsdurchgangshülle enthält; einen Dampfauslassanschluss, der an der Basis des Dampfgenerators angeordnet ist; und einen Luftkasten (218) und Brenner (220) am oberen Ende der Sturzbrandbrennkammerhülle zum Erzeugen von Abgas. 2. Dampfgenerator nach Anspruch 1, wobei das obere Ende der Sturzbrandbrennkammerhülle einen Gaseinlass zum Aufnehmen des Abgases von einer zugeordneten Brennkammer enthält. 3. Dampfgenerator nach Anspruch 1 oder 2, wobei das Abgas, das die Konvektionsdurchgangshülle verlässt, zu einem oder zu mehreren derGruppe wieder in Umlauf gebrachtwird, die Folgendes umfasst: das obere Ende der Sturzbrandbrennkammerhülle; eine Basis der Sturzbrandbrennkammerhülle und eine Basis der Konvektionsdurchgangshülle. 4. Dampfgenerator nach einem der vorhergehenden Ansprüche, wobei das Abgas, das die Konvektionsdurchgangshülle verlässt, durch eines oder durch mehrere strömt, die aus der Gruppe ausgewählt sind, die Folgendes umfasst: einen Regenerativluftwärmer (1142) und eine Partikelreinigungsvorrichtung; und daraufhin zum oberen Ende der Sturzbrandbrennkammerhülle, zu einer Basis der Sturzbrandbrennkammerhülle oder zu einer Basis der Konvektionsdurchgangshülle wieder in Umlauf gebracht wird. 5. Dampfgenerator nach einem der vorhergehenden Ansprüche, wobei der Trichtertunnel mit einem hochtemperaturbeständigen Material ausgekleidet ist. 6. Dampfgenerator nach Anspruch 1, wobei sich die versenkte Fördereinrichtung in einer Richtung relativ zum Abgasstrom bewegt, wobei die Richtung aus derGruppe ausgewählt ist, die Folgendes umfasst: in Reihe mit dem Abgasstrom und quer zum Abgasstrom . 7. Dampfgenerator nach einem der vorhergehenden Ansprüche, wobei der Trichtertunnel aus dampfoderwassergekühlten Rohrfeldern (500, 502) gebildet ist. 8. Dampfgenerator nach Anspruch 7, wobei zwischen der Sturzbrandbrennkammerhülle, dem Trichtertunnel und der Konvektionsdurchgangshülle Wassertrogdichtungen (504) vorhanden sind. 9. Dampfgenerator nach einem der vorhergehenden

Ansprüche, wobei das Fluid in den Rohren der Sturzbrandbrennkammerhülle im Gegenstrom zum Abgasstrom strömt. 10. Dampfgenerator nach einem der vorhergehenden Ansprüche, wobei die Konvektionsdurchgangshülle aus Hüllenwänden gebildet ist, die aus dampf- oder wassergekühlten Rohren hergestelltsind, wobei das Kühlfluid in den Rohren der Konvektionsdurchgangshülle im Gleichstrom mit dem Abgasstrom strömt. 11. Dampfgenerator nach einem der vorhergehenden Ansprüche, wobei die horizontalen Rohrbänke in der Konvektionsdurchgangshülle Überhitzer (240), Zwischenüberhitzer (242) und Vorwärmer (244) enthalten. 12. Dampfgenerator nach einem der vorhergehenden Ansprüche, wobei der Dampfgenerator ferner eine Hülle eines oberen, horizontalen Durchgangs umfasst, die mit einem oberen Ende der Konvektionsdurchgangshülle und einem Abwärtsdurchgang verbunden ist, wobei der obere, horizontale Durchgang und der Abwärtsdurchgang zusätzliche Rohrbänke enthalten. 13. Dampfgenerator nach einem der vorhergehenden Ansprüche, wobei der Trichtertunnel durch einen sich nach außen erstreckenden Hals des Bodengasauslasses der Sturzbrandbrennkammerhülle gebildet ist, der sich in ein Bullauge der Bodengaseinlasses der Konvektionsdurchgangshülle erstreckt. 14. Dampfgenerator nach Anspruch 1, wobei der Trichtertunnel eine erste versenkte Kettenfördereinrichtung (474) unter der Sturzbrandbrennkammerhülle und eine zweite versenkte Kettenfördereinrichtung (474) unter der Konvektionsdurchgangshülle enthält, wobei die erste und die zweite versenkte Kettenfördereinrichtung quer zum Abgasstrom ausgerichtet sind, wobei eine Basis (412) der Sturzbrandbrennkammerhülle abgeschrägt ist, um die Asche/Schlacke in die erste versenkte Kettenfördereinrichtung zu lenken, und eine Basis (432) der Konvektionsdurchgangshülle abgeschrägt ist, um die Asche/Schlacke in die zweite versenkte Kettenfördereinrichtung zu lenken. 15. Dampfgenerator nach Anspruch 1, wobei die versenkte Kettenfördereinrichtung in Reihe mit dem Abgasstrom ausgerichtet ist und sowohl unter der Sturzbrandbrennkammerhülle als auch unter der Konvektionsdurchgangshülle hindurchführt.

Revendications 1. Générateur (200) de vapeur, comportant : une enceinte (210) de four à courant descendant formée de parois (216) constituées de tubes refroidis à l’eau ou à la vapeur, et les parois du four définissant une extrémité supérieure (212) et une sortie de gaz inférieure ; une enceinte (230) de passage de convection comprenant une entrée de gaz inférieure et des blocs de tubes horizontaux situés au-dessus de l’entrée de gaz inférieure ; un tunnel (270) à trémie reliant la sortie de gaz inférieure de l’enceinte de four à courant descendant à l’entrée de gaz inférieure de l’enceinte de passage de convection, le tunnel à trémie comprenant au moins un convoyeur (274) à chaîne submergé servant à évacuer la cendre et les scories de l’enceinte de four à courant descendant et de l’enceinte de passage de convection ; un terminal de sortie de vapeur situé à la base du générateur de vapeur ; et une boîte (218) à vent et des brûleurs (220) à l’extrémité supérieure de l’enceinte de four à courant descendant, servant à générer du gaz de combustion. 2. Générateur de vapeur selon la revendication 1, l’extrémité supérieure de l’enceinte de four à courant descendant comprenant une entrée de gaz servant à recevoir du gaz de combustion provenant d’un four associé. 3. Générateur de vapeur selon la revendication 1 ou 2, du gaz de combustion qui quitte l’enceinte de passage de convection étant recyclé vers un ou plusieurs éléments du groupe comprenant : l’extrémité supérieure de l’enceinte de four à courant descendant ; une base de l’enceinte de four à courant descendant ; et une base de l’enceinte de passage de convection. 4. Générateur de vapeur selon l’une quelconque des revendications précédentes, du gaz de combustion qui quitte l’enceinte de passage de convection passant à travers un ou plusieurs éléments choisis dans le groupe comprenant : un réchauffeur (1142) d’air à récupération ; et un dispositif de nettoyage de particules ; et étant ensuite recyclé vers l’extrémité supérieure de l’enceinte de four à courant descendant, une base de l’enceinte de four à courant descendant, ou une base de l’enceinte de passage de convection. 5. Générateur de vapeur selon l’une quelconque des revendications précédentes, le tunnel à trémie étant revêtu d’un matériau réfractaire. 6. Générateur de vapeur selon la revendication 1, le convoyeur à chaîne submergé avançant dans une direction par rapport à l’écoulement de gaz de combustion, la direction étant choisie dans le groupe comprenant : dans l’alignement de l’écoulement de gaz de combustion ; et transverse à l’écoulement de gaz de combustion. 7. Générateur de vapeur selon l’une quelconque des revendications précédentes, le tunnel à trémie étant formé de panneaux (500, 502) de tubes refroidis à la vapeur ou à l’eau. 8. Générateur de vapeur selon la revendication 7, des joints (504) à goulottes d’eau étant présents entre l’enceinte de four à courant descendant, le tunnel à trémie et l’enceinte de passage de convection. 9. Générateur de vapeur selon l’une quelconque des revendications précédentes, du fluide dans les tubes de l’enceinte de four à courant descendant circulant à contre-courant de l’écoulement de gaz de combustion. 10. Générateur de vapeur selon l’une quelconque des revendications précédentes, l’enceinte de passage de convection étant formée de parois d’enceinte constituées de tubes refroidis à la vapeur ou à l’eau, le fluide de refroidissement dans les tubes de l’enceinte de passage de convection circulant à co-cou-rant de l’écoulement de gaz de combustion. 11. Générateur de vapeur selon l’une quelconque des revendications précédentes, les blocs de tubes horizontaux dans l’enceinte de passage de convection comprenant des surchauffeurs (240), des réchauffeurs (242) et des économiseurs (244). 12. Générateur de vapeur selon l’une quelconque des revendications précédentes, le générateur de vapeur comportant en outre une enceinte de passage horizontal supérieur reliée à une extrémité supérieure de l’enceinte de passage de convection et un passage descendant, le passage horizontal supérieur et le passage descendant contenant des blocs de tubes supplémentaires. 13. Générateur de vapeur selon l’une quelconque des revendications précédentes, le tunnel à trémie est formé par un col s’étendant vers l’extérieurde la sortie de gaz inférieure de l’enceinte de four à courant descendant qui s’étend jusque dans un orifice de l’entrée de gaz inférieure de l’enceinte de passage de convection. 14. Générateur de vapeur selon la revendication 1, le tunnel à trémie comprenant un premier convoyeur (474) à chaîne submergé au-dessous de l’enceinte de four à courant descendant, et un deuxième convoyeur (474) à chaîne submergé au-dessous de l’enceinte de passage de convection, les premier et deuxième convoyeurs à chaîne submergés étant orientés transversalement à l’écoulement de gaz de combustion, une base (412) de l’enceinte de four à courant descendant étant inclinée pour guider la cendre/lesscoriesjusquedans le premier convoyeur à chaîne submergé, et une base (432) de l’enceinte de passage de convection étant inclinée pourguider la cendre/les scories jusque dans le deuxième convoyeur à chaîne submergé. 15. Générateur de vapeur selon la revendication 1, le convoyeur à chaîne submergé étant orienté dans l’alignement de l’écoulement de gaz de combustion et passant à la fois au-dessous de l’enceinte de four à courant descendant et de l’enceinte de passage de convection.

REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is for the reader’s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description • US 2013239909A1 [0007] · US 2009188448 A1 [0007]

Non-patent literature cited in the description • Steam/its generation and use. The Babcock & Wilcox · Steam/its generation and use. The Babcock & Wilcox

Company, 1992 [0035] Company, 2005 [0035]

Claims

? 'ovAs »fk,«.; rttrr vw ΚΛ * ?, ν? οκ «.ΓπκΓί> ő ener x x x of ez ez ez gs gs gs gs gs gs gs gs gs gs gs gs gs gs gs gs gs gs á á <<<<<<<öz öz öz öz 20 20 20 (chaos: a fire barrier (2 Hl) of a descending mite, a sand made of water <·, a pipe with a steam-cooled pipe, "21", where an upper end of the dome defines 12 l 21 and a lower gas family; 230), comprising a lower gas station and a horizontal rain row above the bottom gas inlet; the lowered air stream (274) would run down and the descending air stream would be discharged to the slag outlet: the fezferksrsrail and the cannulae runners would be equipped with a goggle-mounted connector at the bottom of the gauge generator, and & at its upper end, arranges a siphon sheath 21 21 and burners (220) for producing a paint gas.

2, The vapor generator according to claim 1, from which the upper end of the descending airflow chamber includes a gas inlet for receiving gas from an associated water.

3, Coal 1 or 2! gösgeneraior, where the gaseous effluent leaving the convective heat exchanger is reclaimed for at least one of the top end of the descending airflow chamber, the bottom of the descending air flow chamber and the bottom of the Wtevéksívu-kuca-ktmHa.

A steam generator according to any one of the preceding claims, wherein the flue gas exiting the lubricant line passes through at least one of a group consisting of a regenerative nerve heat 11142); then yisszakaringtefesre brush! to the top end of the descending bridgehead bedrock, to the bottom of the descending glow cavity, and to the bottom. to the bottom of the convective gas chamber.

5, A steam generator according to any one of the preceding Claims, wherein the steam generators are lined with a resistant material, «V 1,« é 'tpöi í' ·, '·, !! Zi zgenesaa s ano t with A α, ι, η, he, j, ea xíoow 's <". <' ·? Adod á im dy im im im im im im im im im im im im im im im im im im im im im ből ből ből ből ből ből wild selected.

7, according to any one of the preceding claims. gözgeneráier where «form η / ,, nor vuhotcsó esöpanelék (OTIO, AO2), §, 7, gozpeneteiöb claim wherein the landing legáráfeá ígziárkamrá» á between the garsiaksgnnn garáfalágnt and á-yonvektMutzatn claws vizvályhls seals are ÍSb4s. HE. In the previous claims, a series of vapor vapor generators is provided, where the fluid flow of the fluid in the descending airframe of the descending airflow flows in a stream of elbow gas. V -V efezo ígcaspóö.iok iwu plane é <; asm is the chamber scales formed by the 1 ontsa, övhaean.'lananan, v int viscosity tubes, and to the koovcktivimzam'kaínin the tubes are flowing through the refrigerant fluid stream.

11, Previous Claims Iferipeiyihé Serrite Greasefeeder, abc ·! the kovekuvhozmprkntaráh & tt & , s'n'icx esC ^ aok toife'vdőkef top p, d'e «e,? o. Αν Ί vnteg <s,> i> h nm-b u to t2. And a demanding gmgm of any one of the gmíms, from which the steam mover also includes a top zinc "zínleshnzam4íaznrá" coupled with the veil of the cavity, as well as a descending homeland, where the upper-horizontal draft and the condominium go further.

13, any of the preceding claims: any serrite vapor generator. where the garage tunnel is the exterior widening salty of the first gas climates of the ventricular airflow chamber chamber, letting the ss coovective buzam &

14. The Lsgateof: serii gÖ: zgeíseráíz> The sublime of the gafeitaisgő in the schema iégaxsitxssX xaseéfkaxjtxs is the first lowered syllable lane (474), and beneath the kenvektivhuzanvkamra is a second lobe of the lesion of heat, and where does it go? the second fesolix is the word. In addition, the siphon (412) of the descending airflow chamber chamber is slanted for introduction of hansi / slags into the chain of the eisss slices, and the bottom of the convection boss chamber (432) is also sloped for introduction into the second runner. . 15 The lacquer 11 of the serpentine vapor gasset of the javelin lattice 1, the laceration of the lacquer, is arranged in a line and passes through the descending air stream chamber chamber and the convective wire chamber ss.